Wire-powder composite ultrasonic-assisted additive and subtractive material forming device and manufacturing method

Abstract

The invention discloses a wire-powder composite ultrasonic-assisted additive and subtractive material forming device and a manufacturing method, the wire-powder composite ultrasonic-assisted additive and subtractive material forming device comprises a rack, an additive manufacturing module, a subtractive material milling module, an ultrasonic-assisted module and a forming platform, the rack comprises a Z1-axis assembly, a Z2-axis assembly and an XY plane moving platform; the additive manufacturing module is fixed to the Z1-axis assembly, and the subtractive milling module is fixed to the Z2-axis assembly. The ultrasonic auxiliary module comprises an ultrasonic generator, an ultrasonic vibration head and a mounting frame; the mounting frame is fixed on the XY plane moving platform, and a thrust cylinder is fixed in the inner space of the mounting frame; in the additive manufacturing process, the thrust air cylinder pushes the ultrasonic vibration head to move along the guide rail, so that the ultrasonic vibration head upwards penetrates through the middle hole of the mounting frame and then is vertically pressed on the lower surface of the forming platform, and vibration of the ultrasonic vibration head is controlled through the ultrasonic generator. According to the method, the performance and morphology of the part in the manufacturing process can be regulated and controlled, and therefore high-efficiency and high-quality integrated forming of a complex structure is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a wire-powder composite ultrasonic-assisted additive and subtractive manufacturing device and manufacturing method. Background Art

[0002] Complex structure parts have wide application requirements in the fields of aerospace, military, medical, automotive, electric power, etc. They play an irreplaceable and important role in increasing the fluid contact surface, achieving structural lightweight, controlling material transportation, optimizing mechanical properties, coordinating connection and assembly, etc. However, it is extremely difficult to manufacture some complex structure parts using traditional methods. Taking the flow path parts of aero-engines as an example, in the manufacturing process of complex parts such as casings, nearly twenty precision components need to be processed separately and then welded together, which has prominent problems such as a long process route, high manufacturing cost, and limited structural reliability.

[0003] The composite additive and subtractive manufacturing technology opens up a new path for the manufacturing of complex components by integrating the process advantages of additive forming and subtractive finishing. This system makes full use of the technical characteristics of additive manufacturing in the construction of complex morphologies, and ensures the dimensional accuracy and surface integrity of key features through machining, forming a process combination with a significant complementary effect. The proposal of the composite additive and subtractive concept reduces the accuracy requirements for the blank manufacturing in the additive process. In addition, after the combination of the two processes, since the position of the blank is known, tool-free machining can be realized, improving the accuracy of the manufacturing system. Moreover, the blank of additive manufacturing is accurate, and the cutting allowance is greatly reduced compared with direct subtractive manufacturing, and the possible support structure in additive manufacturing can be directly removed on the machine. Further, the collaborative implementation of multiple additive processes in composite manufacturing can achieve the optimal process combination according to the functional characteristics of the component, promoting the high-efficiency and precision manufacturing of complex structures.

[0004] For example, Chinese patent document with publication number CN110328366A discloses a desktop additive and subtractive composite printing manufacturing device. The printing workbench is installed on the workbench moving device, and the workbench moving device drives the printing workbench to move back and forth between the additive device and the subtractive device for printing operations.

[0005] Chinese patent document with publication number CN106735216A discloses an additive and subtractive composite manufacturing equipment for metal parts, which includes an additive manufacturing component, a subtractive manufacturing component, an atmosphere control component, and a control system. The additive manufacturing component is used to perform selective laser melting on the part to be processed; the subtractive manufacturing component is used to perform machining on the sliced layer of the metal part that has been melted and formed; the atmosphere control component is used to provide a protective gas for the laser irradiation area and remove the metal fumes generated in the laser irradiation area during the part manufacturing process; the control system is used to process the CAD model of the metal part to be formed, generate the processing trajectories of the additive manufacturing component and the subtractive manufacturing component, and drive the operation of each part of the equipment.

[0006] However, the existing composite manufacturing technology still faces major technical challenges: Microscopic defects are likely to occur in the interface bonding area formed during the multi-process alternation (including additive-additive interfaces and additive-subtractive interfaces in different ways), resulting in a gradient weakening effect on the structural performance, which severely restricts the engineering applicability of the composite manufacturing technology. Summary of the Invention

[0007] Aiming at the technical problems existing in the prior art, the present invention provides a wire-powder composite ultrasonic-assisted additive-subtractive forming device and manufacturing method, which can regulate the performance and morphology of parts during the manufacturing process, so as to realize the high-efficiency and high-quality integrated forming of complex structures.

[0008] A wire-powder composite ultrasonic-assisted additive-subtractive forming device includes a frame, an additive manufacturing module, a subtractive milling module, an ultrasonic assistance module, and a forming platform. The frame includes a Z1-axis assembly, a Z2-axis assembly, and an XY-plane moving platform; The additive manufacturing module is fixed on the Z1-axis assembly. The additive manufacturing module includes an additive module mounting plate and a laser cladding module using powder as raw material and a laser wire melting module using wire as raw material, which are fixed on the additive module mounting plate; The subtractive milling module is fixed on the Z2-axis assembly. The subtractive milling module includes an electric spindle and an end mill; The ultrasonic assistance module includes an ultrasonic generator, an ultrasonic vibration head, and a mounting frame; The mounting frame is fixed on the XY-plane moving platform. A pushing cylinder and a guide rail with a slider are fixed in the inner space of the mounting frame; The ultrasonic vibration head is fixed on the slider and connected to the output shaft of the pushing cylinder; The forming platform is fixed on the upper surface of the mounting frame. During the additive manufacturing process, the pushing cylinder pushes the ultrasonic vibration head to move along the guide rail, so that the ultrasonic vibration head passes through the middle hole of the mounting frame upward and vertically presses on the lower surface of the forming platform, and the vibration of the ultrasonic vibration head is controlled by the ultrasonic generator.

[0009] In the present invention, the additive manufacturing module is installed on the Z1-axis assembly, integrating laser cladding, laser wire melting, and wire-powder co-feed modes; the subtractive milling module is installed on the Z2-axis assembly to correct the abnormal surface morphology of the additive layer caused by the ultrasonic process through real-time milling; the ultrasonic assistance module is located on the XY-plane moving platform, and uses the ultrasonic vibration head to transmit energy to the forming platform, and regulates the molten pool flow and solidification through cavitation and acoustic streaming effects to achieve the effects of grain refinement and interface strengthening.

[0010] Further, the Z1-axis assembly includes a Z1 linear motion module and a Z1 main spindle box, and the additive manufacturing module is fixed on the Z1 linear motion module; The Z2-axis component includes a Z2 linear motion module and a Z2 main spindle box, and the subtractive milling module is fixed on the Z2 linear motion module; The XY-plane moving platform includes an X-axis linear motion module, a Y-axis linear motion module and a base. The ultrasonic-assisted module is fixed on the upper surface of the base, and the X-axis linear motion module and the Y-axis linear motion module jointly drive the base and the ultrasonic-assisted module to move freely in the XY plane.

[0011] Furthermore, the additive manufacturing module further includes a visual monitoring module, which is installed at the rear side of the additive module mounting plate and is used for on-line monitoring of the surface topography of the deposition layer during the additive and subtractive manufacturing process.

[0012] Furthermore, the laser cladding module includes a laser cladding head, a laser generator, a double-barrel powder feeder, a water cooling system, and an inert gas cylinder; The laser emitted by the laser generator is transmitted through an optical fiber and emitted from the nozzle of the laser cladding head to form a laser beam on the forming platform; the double-barrel powder feeder is equipped with two independent powder barrels for placing different powders. The double-barrel powder feeder is connected to the laser cladding head through an air pipe. The powder ejected from the nozzle of the laser cladding head converges on the forming platform and coincides with the laser beam to form a powder deposition layer; the inert gas cylinder provides a transport gas for transporting the powder for the double-barrel powder feeder and at the same time provides an inert gas environment for the additive manufacturing process; the water cooling system is connected to the laser generator through a water pipe and is used for cooling the laser generator.

[0013] Furthermore, the laser wire module includes a connection block, a laser wire rod and a wire feeding mechanism; The laser wire rod is connected to the laser cladding head through the connection block, and the angle between the laser wire rod and the laser cladding head is adjusted by rotating the knob on the connection block; the wire feeding mechanism uses the friction force generated by the wire feeding wheel to transport the wire through the wire feeding pipe into the laser wire rod. The wire extends out of the laser wire rod and contacts the forming platform. At this time, the center of the wire coincides with the center of the laser beam to form a wire deposition layer.

[0014] Preferably, the frequency of the ultrasonic vibration head is 20 kHz, the amplitude adjustment range is 0 - 35 μm, and the pressure adjustment range of the pushing air cylinder is 0 - 0.2 MPa; the ultrasonic intensity is adjusted by adjusting the amplitude and the air cylinder pressure.

[0015] A wire-powder composite ultrasonic-assisted additive and subtractive forming manufacturing method, using the above-mentioned wire-powder composite ultrasonic-assisted additive and subtractive forming device, includes the following steps: S1. Load the metal powder and ceramic particles into two powder cylinders of the laser cladding module respectively, and place the metal wire into the wire feeding mechanism of the laser wire melting module; adjust the nozzle height of the laser cladding head in the laser cladding module to keep a certain distance from the forming platform. At the same time, adjust the laser emitted by the laser generator in the laser cladding module, and finely adjust the laser spot focus, powder focus and the center point of the wire until the three coincide. S2. Plan the additive manufacturing path and method for the part to be prepared, and further obtain the additive manufacturing slice information of the printing model. S3. Turn on the ultrasonic generator to make the ultrasonic act on the forming platform, and then carry out additive manufacturing on the forming platform; according to the model additive manufacturing slice information, the additive manufacturing module successively performs laser cladding additive manufacturing, laser wire melting additive manufacturing and wire-powder co-feed additive manufacturing at preset positions until one layer of printing is completed. S4. Use the vision monitoring module to measure the surface roughness of the current deposited layer, and send the measured value to the industrial control computer for comparison with the set threshold. S5. If the surface roughness of the current deposited layer is greater than the set threshold, the additive manufacturing is interrupted and the ultrasonic generator is turned off. Move the forming platform to the subtractive machining station corresponding to the Z2-axis component. The subtractive milling module mills the surface of the current deposited layer according to the path planning. After the subtractive machining is completed, move the forming platform to the additive manufacturing station corresponding to the Z1-axis component, turn on the ultrasonic generator and perform the additive manufacturing of the next layer; if the surface roughness of the current deposited layer is less than the set threshold, directly perform the additive manufacturing of the next layer. S6. Repeat S4 - S5 until the entire model printing is completed.

[0016] In step S2, the additive manufacturing methods include: laser cladding additive manufacturing with metal powder as the raw material, laser wire melting additive manufacturing with metal wire as the raw material, and wire-powder co-feed additive manufacturing with synchronous feeding of metal wire and ceramic powder; during the additive manufacturing planning, according to the structural characteristics, functional requirements and process cost optimization indicators of the part to be prepared, use the multi-objective decision-making algorithm to select the appropriate additive manufacturing method.

[0017] During the wire-powder co-feed additive manufacturing process, by adjusting the powder feeding rate of the ceramic powder in real time, the gradient distribution of the ceramic phase content in the metal matrix composite coating is realized; among them, the ceramic mass fraction in the area adjacent to the metal matrix surface of the coating is low, and with the increase of the distance, the content of the ceramic phase increases in a gradient manner.

[0018] In steps S3 and S5, during the additive manufacturing process, turn on the ultrasonic generator, and the ultrasonic vibration head applies the cavitation effect and acoustic streaming effect of the ultrasonic to the liquid melt pool on the forming platform, so that the liquid melt pool solidifies under the continuous action of the ultrasonic energy field; the rough surface formed during the ultrasonic solidification process is removed by the subtractive milling module through milling operations.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. For the features and requirements of different parts of complex parts, the device of the present invention can intelligently combine three additive manufacturing methods: laser wire additive rapid prototyping for large-size structures, laser cladding additive precision manufacturing for fine features, and wear-resistant gradient coating formation in the peripheral area by wire-powder hybrid laser additive. This method of matching processing means on demand not only significantly improves the overall manufacturing efficiency but also effectively ensures the forming accuracy and performance of key details.

[0020] 2. In the present invention, the ultrasonic-assisted additive and subtractive manufacturing technology helps to reduce the defects at the bonding interface, thus significantly improving the interface bonding strength. In addition, in wire-powder co-feed additive manufacturing, ultrasound can not only promote the uniform distribution of ceramic reinforcement phases within the same layer but also enhance the mass exchange efficiency between different gradient layers. This effect helps to relieve the interlayer stress concentration and performance differences and reduce the risk of coating cracking, thereby greatly improving the overall performance of the gradient coating.

[0021] 3. In the present invention, during the ultrasonic-assisted additive manufacturing process, active in-situ milling is used to perform active geometric correction on the additive layer. Through the closed-loop control of online topography monitoring and dynamic compensation milling, an active quality control system for multiple process links is formed. While retaining the grain refinement and stress regulation effects caused by ultrasonic treatment, this system eliminates the accumulation of surface waviness and geometric errors of the cladding layer. By this method, the application range of ultrasonic process parameters can be significantly expanded, breaking through the mutual restriction between the process stability and forming quality of traditional single processes, and thus realizing the synchronous optimization of the surface integrity and mechanical properties of parts under the action of the ultrasonic energy field. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic structural diagram of the wire-powder composite ultrasonic-assisted additive and subtractive forming device in the embodiment of the present invention.

[0023] Figure 2 is Figure 1 Schematic diagram of the frame part in

[0024] Figure 3 Schematic structural diagram of the ultrasonic-assisted module in the embodiment of the present invention.

[0025] Figure 4 Schematic structural diagram of the additive manufacturing module in the embodiment of the present invention.

[0026] Figure 5 Schematic diagram of wire-powder composite ultrasonic-assisted additive and subtractive forming of a 316L radiator in the embodiment of the present invention.

[0027] Figure 6 Flowchart of the wire-powder composite ultrasonic-assisted additive and subtractive forming manufacturing method in the embodiment of the present invention.

[0028] In the figure: 1 - frame, 2 - ultrasonic assistance module, 3 - forming platform, 4 - laser cladding module, 5 - laser wire melting module, 6 - vision monitoring module, 7 - additive module mounting plate, 8 - electric spindle, 9 - end mill, 10 - Z1 linear motion module, 11 - Z1 spindle headstock, 12 - Z2 linear motion module, 13 - Z2 spindle headstock, 14 - X-axis linear motion module, 15 - Y-axis linear motion module, 16 - base, 17 - industrial control computer, 21 - ultrasonic generator, 22 - ultrasonic vibration head, 23 - push cylinder, 24 - slider, 25 - mounting frame, 41 - laser cladding head, 42 - laser generator, 43 - double-barrel powder feeder, 44 - water cooling system, 45 - inert gas cylinder, 51 - connecting block, 52 - laser wire melting rod, 53 - wire feeding mechanism. Specific implementation mode

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are intended to facilitate the understanding of the present invention, but do not limit it in any way.

[0030] As Figures 1 to 2 shown, a wire-powder composite ultrasonic-assisted additive and subtractive manufacturing device includes a frame 1, an additive manufacturing module, a subtractive milling module, an ultrasonic assistance module 2, and a forming platform 3. The frame 1 adopts a double-spindle vertical machining center frame, including a Z1-axis assembly, a Z2-axis assembly, and an XY-plane moving platform.

[0031] The additive manufacturing module is installed on the Z1-axis assembly, the subtractive milling module is installed on the Z2-axis assembly, and the ultrasonic assistance module is installed on the XY-plane moving platform.

[0032] The additive manufacturing module includes a laser cladding module 4 using powder as the raw material, a laser wire melting module 5 using wire as the raw material, a vision monitoring module 6, and an additive module mounting plate 7. The vision monitoring module 6 is installed at the rear side of the additive module mounting plate 7 for online monitoring of the surface topography of the deposition layer during the additive and subtractive manufacturing process.

[0033] The subtractive milling module includes an electric spindle 8 and an end mill 9, and the electric spindle 8 drives the end mill 9 to rotate for milling operations.

[0034] As Figure 1 and Figure 3As shown in the figure, the ultrasonic assistance module 2 includes an ultrasonic generator 21, an ultrasonic vibration head 22, a pushing cylinder 23, a slider 24, and a mounting frame 25. The ultrasonic generator 21 is connected to the ultrasonic vibration head 22 through a high-voltage coaxial cable to control the ultrasonic vibration head 22 to output ultrasonic waves acting on the forming platform 3. The forming platform 3 is a square substrate made of 316L material, installed on the upper surface of the mounting frame 25, and the rest of the devices are located directly below the upper surface of the mounting frame 25. The ultrasonic vibration head 22 is fixed on the slider 24. During the additive manufacturing process, the pushing cylinder 23 pushes the ultrasonic vibration head 22 to move along the guide rail, so that it passes through the middle hole of the mounting frame 25 and vertically presses on the lower surface of the forming platform 3, effectively promoting the transmission of ultrasonic vibration through the forming platform 3 to the molten pool.

[0035] The Z1-axis assembly consists of a Z1 linear motion module 10 and a Z1 main spindle box 11. The Z1 linear motion module 10 is fixedly connected to the additive manufacturing module mounting plate 7. The Z1 linear motion module 10 is connected to the Z1 main spindle box 11 to drive the additive manufacturing module on the additive manufacturing module mounting plate 7 to move in the Z-axis direction.

[0036] The Z2-axis assembly consists of a Z2 linear motion module 12 and a Z2 main spindle box 13. The Z2 linear motion module 12 is fixedly connected to the subtractive milling module. The linear motion module Z2 is connected to the main spindle box Z2 to drive the subtractive milling module to move in the Z-axis direction.

[0037] The XY-plane moving platform consists of an X-axis linear motion module 14, a Y-axis linear motion module 15, and a base 16. The X-axis linear motion module 14 and the Y-axis linear motion module 15 jointly drive the base 16 and the ultrasonic assistance module 2 fixed on the upper surface of the base 16 to move freely in the XY plane.

[0038] As Figure 1 and Figure 4As shown in the figure, the laser cladding module 4 includes a laser cladding head 41, a laser generator 42, a double-barrel powder feeder 43, a water cooling system 44, and an inert gas cylinder 45. The laser generator 42 is connected to the laser cladding head 41 through an optical fiber. The laser emitted by the laser generator 42 is emitted from the nozzle of the laser cladding head 41 through the optical path system, and a laser beam is formed on the forming platform 3. The double-barrel powder feeder 43 is equipped with two independent powder barrels for installing different powders. The double-barrel powder feeder 43 is connected to the laser cladding head 41 through an air pipe. The powder ejected from the nozzle of the laser cladding head 41 converges on the forming platform 3 and coincides with the laser beam to form a powder deposition layer. High-purity argon is stored in the inert gas cylinder 45. One side of the inert gas cylinder 45 is connected to the double-barrel powder feeder 43, which blows the cladding powder into the molten pool as a transport gas, and the gas flow rate is 9 L / min. The other side is connected to the nozzle of the laser cladding head 41, which provides an inert gas environment for the additive manufacturing process as a protective gas, and the gas flow rate is 15 L / min. The water cooling system 44 is connected to the laser generator 42 through a water pipe and is used to cool the laser generator 42.

[0039] As Figure 1 and Figure 4 shown in the figure, the laser wire melting module includes an L-shaped connecting block 51, a laser wire melting rod 52, and a wire feeding mechanism 53. The laser wire melting rod 52 is connected to the laser cladding head 41 through the L-shaped connecting block 51. The angle between the laser wire melting rod 52 and the laser cladding head 41 can be adjusted by rotating the knob on the connecting block 51, and the preferred angle is 45°. The laser cladding head 41 and the laser wire melting rod 52 are fixedly connected to the front side of the additive manufacturing module mounting plate 7. The wire feeding mechanism 53 uses the friction generated by the wire feeding wheel to transport the wire through the wire feeding pipe into the laser wire melting rod 52. After the wire extends out of the laser wire melting rod 52, it contacts the forming platform 3. At this time, the center of the wire coincides with the center of the laser beam to form a wire deposition layer.

[0040] The mounting frame 25 of the ultrasonic assisted module 2 is fixedly connected to the base 16 on the XY plane moving platform. The frequency of the ultrasonic vibration head 22 is 20 kHz, and the amplitude adjustment range is 0 - 35 μm. The pressure adjustment range of the pushing air cylinder 23 is 0 - 0.2 MPa. The ultrasonic intensity can be adjusted by adjusting the amplitude and the cylinder pressure.

[0041] As Figure 6 shown in the figure, a wire-powder composite ultrasonic assisted additive and subtractive forming manufacturing method uses the above-mentioned wire-powder composite ultrasonic assisted additive and subtractive forming device, and includes the following steps: S1, load 316L metal powder and WC ceramic particles into two powder barrels respectively, and put a 316L metal wire with a diameter of 1.2 mm into the wire feeding mechanism 53. Adjust the nozzle height of the laser cladding head 41 so that the distance from the forming platform 3 is 17 mm. At the same time, finely adjust the laser spot focus, powder focus, and the center point of the wire until the three coincide.

[0042] S2. Plan the additive manufacturing path and method for the radiator model, and import the additive manufacturing slice information of the printed model into the industrial control computer 17 of the preparation device.

[0043] S3. Turn on the ultrasonic generator 21 to apply ultrasonic waves to the forming platform 3, and then perform additive manufacturing on the forming platform 3. The additive manufacturing module performs laser cladding additive manufacturing, laser wire additive manufacturing, and wire-powder co-feed additive manufacturing at preset positions in sequence according to the model slice information until one layer of printing is completed. The layer height is preferably 0.5 mm.

[0044] S4. The vision monitoring module 6 measures the surface roughness of the current deposited layer and sends the measured value to the industrial control computer 17 for comparison with the set threshold. The threshold is based on the peak-to-valley height (PV), and the set threshold is 100 μm.

[0045] S5. If the surface roughness of the current deposited layer is greater than the set threshold, the additive manufacturing is interrupted and the ultrasonic is turned off. The forming platform 3 is moved to the subtractive machining station corresponding to the Z2-axis assembly. The subtractive milling module performs milling operations on the upper surface of the current deposited layer according to the path planning. The milling parameters are set as a rotational speed of 1700 r / min and a feed rate of 700 mm / min. After the subtractive machining is completed, the forming platform is moved to the additive manufacturing station corresponding to the Z1-axis assembly, the ultrasonic is turned on, and the additive manufacturing of the next layer is carried out. If the surface roughness of the current deposited layer is less than the set threshold, the additive manufacturing of the next layer is directly carried out.

[0046] In step S2, the additive manufacturing methods are mainly divided into three types: one is laser cladding additive manufacturing, which uses 316L metal powder as the raw material for printing the fine heat dissipation structure in the center of the radiator. The specific forming parameters are a laser power of 800 W, a scanning speed of 500 mm / min, and a powder feeding rate of 8 g / min. The second is laser wire additive manufacturing, which uses 316L metal wire as the raw material for printing the radiator shell and the fixed end. The specific forming parameters are a laser power of 1750 W, a scanning speed of 500 mm / min, and a wire feeding rate of 90 cm / min. The third is wire-powder co-feed additive manufacturing. Through the synchronous feeding of 316L metal wire and WC ceramic powder, the preparation of a high-hardness and wear-resistant metal matrix composite coating on the outermost side of the radiator shell can be realized. The specific forming parameters are a laser power of 1750 W, a scanning speed of 500 mm / min, a wire feeding rate of 90 cm / min, and the powder feeding rate is adjusted in real time. During the additive manufacturing planning, according to the structural characteristics, functional requirements, and process cost optimization indicators of the part to be prepared, the multi-objective decision-making algorithm can be used to select the most suitable additive manufacturing method, so as to realize the efficient and integrated forming of the whole process of the composite material.

[0047] Such as Figure 5As shown, it demonstrates the wire-powder composite integrated forming method for the 316L radiator in this embodiment. In wire-powder co-feed additive manufacturing, by adjusting the powder feeding rate of ceramic powder in real time, a gradient distribution of the ceramic phase content in the metal matrix composite coating can be achieved: three composite coatings are cladded on the outer side of the radiator shell. The first layer is connected to the radiator shell, with a WC content of 15 wt.%, and the powder feeding rate is 1.4 g / min at this time; the WC content of the middle layer is 25 wt.%, and the powder feeding rate is 2.7 g / min at this time; the WC content of the outermost layer is 35 wt.%, and the powder feeding rate is 4.3 g / min at this time. This gradient distribution method helps to improve the bonding strength of the interface, reduce the risk of material cracking, and can also significantly improve the hardness and wear resistance of the coating.

[0048] In steps S3 - S5, during the additive manufacturing process, ultrasonic waves are turned on, and the cavitation effect and acoustic streaming effect of ultrasonic waves are applied to the liquid melt pool, so that the melt pool solidifies under the continuous action of the ultrasonic energy field. The specific parameters of the ultrasonic waves are an ultrasonic amplitude of 25 μm, an ultrasonic frequency of 20 kHz, and a cylinder air pressure of 0.05 MPa. As the ultrasonic intensity increases, the part performance is improved to a certain extent. However, ultrasonic waves may cause melt pool disturbance and surface quality deterioration, thereby increasing the surface roughness of the deposition layer and reducing the printability. To overcome this problem, an in-situ milling process is introduced during the ultrasonic-assisted additive manufacturing process, which can effectively eliminate the morphological uncertainty caused by ultrasonic waves and expand the adjustable range of ultrasonic intensity (the ultrasonic amplitude can be increased to 35 μm, and the cylinder air pressure can be increased to 0.1 MPa), so as to achieve a balance between part performance and printability.

[0049] In the preparation of the radiator, the powder material can be changed from 316L to CuCrZr, which can greatly improve the heat dissipation capacity of the radiator.

[0050] In the present invention, the additive manufacturing module integrates three forming modes: laser cladding additive manufacturing, laser wire additive manufacturing, and wire-powder co-feed additive manufacturing, breaking through the process limitations of traditional composite manufacturing with a single additive method, and realizing the composite manufacturing ability with both material diversity and structural adaptability. At the same time, by introducing the ultrasonic-assisted module 2, the ultrasonic energy field is used to dynamically regulate the metallurgical behavior of the melt pool - using the micro-jet generated by the cavitation effect to accelerate the mass transfer of the melt liquid phase, and coordinating with the forced convection effect caused by the acoustic streaming effect to effectively break the dendrite growth while reducing the temperature gradient of the melt pool, achieving the dual goals of grain refinement and interface strengthening. At the same time, ultrasonic waves can also promote the uniform dispersion of ceramic reinforcing phases in the composite material. Furthermore, the present invention integrates a subtractive milling module to construct a self-feedback process chain, and by removing the surface wave marks of the cladding layer that may be caused by the ultrasonic process in real time, a synergistic action mechanism of energy field strengthening and surface finishing is formed, significantly improving the formability and surface quality of complex feature structures.

[0051] The above-described embodiments have elaborated in detail the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modification, supplement, and equivalent replacement made within the scope of the principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A silk-powder composite ultrasonic-assisted additive and subtractive manufacturing device, characterized in that It includes a frame (1), an additive manufacturing module, a subtractive milling module, an ultrasonic assistance module (2), and a forming platform. The frame (1) includes a Z1-axis assembly, a Z2-axis assembly, and an XY-plane moving platform; The additive manufacturing module is fixed on the Z1-axis assembly. The additive manufacturing module includes an additive module mounting plate (7) fixed to the Z1-axis assembly, and a laser cladding module (4) using powder as raw material and a laser wire feeding module (5) using wire as raw material, both of which are fixed on the additive module mounting plate (7); The subtractive milling module is fixed on the Z2-axis assembly. The subtractive milling module includes an electric spindle (8) and an end mill (9); The ultrasonic assistance module (2) includes an ultrasonic generator (21), an ultrasonic vibration head (22), and a mounting frame (25); the mounting frame (25) is fixed on the XY-plane moving platform. Inside the mounting frame (25), a pushing cylinder (23) and a guide rail with a slider (24) are fixed; the ultrasonic vibration head (22) is fixed on the slider (24) and connected to the output shaft of the pushing cylinder (23); The forming platform (3) is fixed on the upper surface of the mounting frame (25). During the additive manufacturing process, the pushing cylinder (23) pushes the ultrasonic vibration head (22) to move along the guide rail, so that the ultrasonic vibration head (22) passes through the middle hole of the mounting frame (25) upward and vertically presses on the lower surface of the forming platform (3), and the vibration of the ultrasonic vibration head (22) is controlled by the ultrasonic generator (21).

2. The wire-powder composite ultrasonic-assisted additive and subtractive manufacturing device according to claim 1, characterized in that, The Z1-axis assembly includes a Z1 linear motion module (10) and a Z1 spindle box (11), and the additive manufacturing module is fixed on the Z1 linear motion module (10); The Z2-axis assembly includes a Z2 linear motion module (12) and a Z2 spindle box (13), and the subtractive milling module is fixed on the Z2 linear motion module (12); The XY-plane moving platform includes an X-axis linear motion module (14), a Y-axis linear motion module (15), and a base (16). The ultrasonic assistance module (2) is fixed on the upper surface of the base (16), and the X-axis linear motion module (14) and the Y-axis linear motion module (15) jointly drive the base (16) and the ultrasonic assistance module (2) to move freely in the XY plane.

3. The wire-powder composite ultrasonic-assisted additive and subtractive manufacturing device according to claim 1, wherein The additive manufacturing module further includes a vision monitoring module (6). The vision monitoring module (6) is installed at the rear side of the additive module mounting plate (7) and is used for on-line monitoring of the surface topography of the deposition layer during the additive and subtractive machining process.

4. The wire-powder composite ultrasonic-assisted additive and subtractive manufacturing device according to claim 1, characterized in that The laser cladding module (4) includes a laser cladding head (41), a laser generator (42), a double-barrel powder feeder (43), a water cooling system (44), and an inert gas cylinder (45); The laser emitted by the laser generator (42) is transmitted through an optical fiber and emitted from the nozzle of the laser cladding head (41), forming a laser beam on the forming platform (3); the double-barrel powder feeder (43) is equipped with two independent powder barrels for placing different powders. The double-barrel powder feeder (43) is connected to the laser cladding head (41) through an air pipe. The powder ejected from the nozzle of the laser cladding head (41) converges on the forming platform (3) and coincides with the laser beam to form a powder deposition layer; the inert gas cylinder (45) provides a transportation gas for transporting the powder for the double-barrel powder feeder (43), and at the same time provides an inert gas environment for the additive manufacturing process; the water cooling system (44) is connected to the laser generator (42) through a water pipe and is used to cool the laser generator (42).

5. The wire-powder composite ultrasonic-assisted additive and subtractive manufacturing device according to claim 4, characterized in that, The laser wire melting module (5) includes a connecting block (51), a laser wire melting rod (52) and a wire feeding mechanism (53); The laser wire melting rod (52) is connected to the laser cladding head (41) through the connecting block (51). The angle between the laser wire melting rod (52) and the laser cladding head (41) is adjusted by rotating the knob on the connecting block (51); the wire feeding mechanism (53) uses the friction force generated by the wire feeding wheel to transport the wire through the wire feeding pipe into the laser wire melting rod (52). After the wire extends out of the laser wire melting rod (52), it contacts the forming platform. At this time, the center of the wire coincides with the center of the laser beam to form a wire deposition layer.

6. The wire-powder composite ultrasonic-assisted additive and subtractive manufacturing device according to claim 1, wherein The frequency of the ultrasonic vibration head (22) is 20 kHz, and the amplitude adjustment range is 0 - 35 μm. The pressure adjustment range of the pushing air cylinder (23) is 0 - 0.2 MPa; the ultrasonic intensity is adjusted by adjusting the amplitude and the air cylinder pressure.

7. A silk-powder composite ultrasonic-assisted additive and subtractive manufacturing method, characterized in that Using the wire-powder composite ultrasonic-assisted additive and subtractive manufacturing device according to any one of claims 1 to 6, includes the following steps: S1, load the metal powder and ceramic particles into the two powder barrels of the laser cladding module (4) respectively, and put the metal wire into the wire feeding mechanism (53) of the laser wire melting module (5); adjust the nozzle height of the laser cladding head (41) in the laser cladding module (4) to keep a certain distance from the forming platform. At the same time, adjust the laser emitted by the laser generator (42) in the laser cladding module (4), and finely adjust the laser spot focus, powder focus and the center point of the wire until the three coincide; S2, plan the additive path and additive method for the part to be prepared, and further obtain the additive slice information of the printing model; S3, turn on the ultrasonic generator (21) to make the ultrasonic act on the forming platform, and then perform additive manufacturing on the forming platform; the additive manufacturing module performs laser cladding additive manufacturing, laser wire melting additive manufacturing and wire-powder co-feed additive manufacturing at the preset position according to the additive slice information of the printing model until one layer of printing is completed; S4, use the visual monitoring module to measure the surface roughness of the current deposition layer, and send the measured value to the industrial control computer (17) for comparison with the set threshold value; S5. If the surface roughness of the current deposited layer is greater than the set threshold, the additive manufacturing is interrupted and the ultrasonic generator (21) is turned off. The forming platform is moved to the subtractive machining station corresponding to the Z2-axis assembly. The subtractive milling module mills the surface of the current deposited layer according to the path planning. After the subtractive machining is completed, the forming platform is moved to the additive manufacturing station corresponding to the Z1-axis assembly, the ultrasonic generator (21) is turned on, and the additive manufacturing of the next layer is carried out. If the surface roughness of the current deposited layer is less than the set threshold, the additive manufacturing of the next layer is directly carried out. S6. Repeat S4 - S5 until the printing of the entire model is completed.

8. The wire-powder composite ultrasonic-assisted additive and subtractive manufacturing method according to claim 7, characterized in that, In step S2, the additive manufacturing methods include: laser cladding additive manufacturing with metal powder as the raw material, laser wire additive manufacturing with metal wire as the raw material, and wire-powder co-feed additive manufacturing with synchronous feeding of metal wire and ceramic powder. During the additive manufacturing planning, according to the structural characteristics, functional requirements, and process cost optimization indicators of the part to be prepared, a multi-objective decision-making algorithm is used to select a suitable additive manufacturing method.

9. The wire-powder composite ultrasonic-assisted additive and subtractive manufacturing method according to claim 8, wherein During the wire-powder co-feed additive manufacturing process, by adjusting the powder feeding rate of the ceramic powder in real time, a gradient distribution of the ceramic phase content in the metal matrix composite coating is achieved. Among them, the ceramic mass fraction in the area adjacent to the metal matrix surface of the coating is low, and with the increase of the distance, the content of the ceramic phase increases gradually in a gradient manner.

10. The wire-powder composite ultrasonic-assisted additive and subtractive manufacturing method according to claim 7, characterized in that In steps S3 and S5, during the additive manufacturing process, the ultrasonic generator (21) is turned on. The ultrasonic vibration head (22) applies the cavitation effect and acoustic streaming effect of ultrasound to the liquid melt pool on the forming platform, so that the liquid melt pool solidifies under the continuous action of the ultrasonic energy field. The rough surface formed during the ultrasonic solidification process is removed by the subtractive milling module through milling operations.

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